There are a variety of fluid connectors in the prior art. The majority of disclosed prior art fluid connectors are designed for quick (tool less) couple and release of a fluid line, usually by the use of latches or flexible fingers which involve additional moving parts and complication. There are many issues surrounding the fluid connector such as, how to handle the many different types of fluids and their properties, such as viscosity, miscibility of the various fluid components, also fluid pressure capability, fluid sealing capabilities at the connector interface, ease of assembly and disassembly, and fluid line interface particulars.
In addressing the above-identified issues that are common to fluid connectors, the prior art discloses a number of different types of connectors. Looking to a typical tool-less fluid connector that includes fluid sealing capabilities, in United Kingdom patent number GB1,193,159 to Sarns disclosed is a molded plastic coupling used with flexible tubing for medical appliances. In Sarns the pinching of the outside diameter of the connector releases the interlock on “L” shaped fingers, wherein a telescoping connection uses male gland o-rings for fluid sealing with the Sarns connector typically being applied to a medical intravenous tube feed fluid communication line for a patient. Another example is in U.S. Pat. No. 6,893,055 to Thomas et al. that discloses a tubing snap connector that utilizes an outside diameter resilient sleeve that acts as a ring retainer also having a male gland o-ring for fluid sealing between the tubing ends. Thomas et al. requires that the sleeve have a spring arm and stop cam combination that radially encompasses a portion of sleeve circumference, thus facilitating assembly without the need for multiple pieces to secure around the tubing outside ridge, however, still having a separable piece. Similarly, in U.S. Pat. No. 4,591,192 to Van Exel et al. disclosed a quick connect coupling for a garden hose that uses line pressure to add friction to the clip that is received into a groove in the male nozzle, thus making the coupling less prone to separating inadvertently under pressure. Van Exel et al., like Thomas et al. still requires separable pieces for the fluid connector to make a removable engagement. Further, being somewhat similar to Sarns, in U.S. Pat. No. 6,543,814 to Bartholomew disclosed is a quick connector for tubing without the need for tools that is fluid tight and allows for swiveling. Bartholomew uses deflectable fingers that are received into a mating annular bead, wherein a locking tab that engages the annular channel to lock the connector, however, again resulting is a complex assembly of parts. Further, in this area in United States patent application publication number US2004/0164547 A1 to Cronley, disclosed is a quick connect coupler for hoses and pipes that uses a plurality of partial threaded segments in the form of flexible fingers. In Cronley, the threaded segments form a flexible collet for non turning required threaded engagement, having again a multitude of parts being required.
Another type of fluid connector is what is called a “luer type” again for use in medical and surgical applications, wherein the luer has a frustroconical shaped outer surface having a fluid passage within the interior of the frustroconical section. Typically a luer type fitting matably engages a male frustroconical outer surface section with a female frustroconical inner surface section in attempting to achieve a substantially fluid removable interface. However, this aforementioned luer type engagement requires ancillary means for axial retention of the luer interface (interspaced between the tubing ends), wherein the luer interface itself has little axial retention other than the surface friction between the male and female frustroconical sections, unfortunately both the taper nature of the luer engagement and any pressure within the fluid line all act to forcibly separate the luer interface axially, resulting in an unacceptable situation for loss of fluid communication between the tubing ends. An example of a means for axial retention of a luer type fitting is in U.S. Pat. No. 4,676,530 to Nordgren et al. that discloses a coupling device for connecting fluid flow conduits to each other with a male luer lock fitting to insure against axial separation. Nordgren et al. uses an inwardly flexibly fingered collet that radially grips the outer tapered section of the male frustroconical section for a easily insertable interface of the frustroconical section by the increasing diameter frustroconical surface moving through the collet fingers, however, Nordgren et al. does not have an easily removable connection as either the fingers and/or male frustroconical outer surface would be damaged. Thus the Nordgren et al. connector is basically a one time use disposable connector.
Further, in this same area of luer type fittings in U.S. Pat. No. 7,014,224 to Sward disclosed is a refinement to the luer type connector for enhanced fluid sealing that includes a fluid line connector for connecting two fluid lines by coupling a male and female portion together with a slip ring to lock the male and female couplers. Sward utilizes the mating of o-ring scalable frustroconical portions that are engaged by a slip ring that is locked by a leaf spring, while being functional at being a fluid sealed connector, does posses a number of parts that add to complexity.
Other special purpose type fluid connectors are disclosed in the prior art such as in U.S. Pat. No. 4,949,745 to McKeon that discloses a connector using two couplers held between a pair of o-rings to produce a fluid path that can be assembled in a contaminated environment without contaminating the fluid, in other word due to internal valving and chambering the fluid within the lines is not exposed to the outside environment, i.e. not being released from the fluid line until the connector is secured together. McKeon utilises a multitude of sealed chambers that prevent exposure of the fluid within the connector to the external environment during the connecting and disconnecting of the couplers, however, resulting in a highly complex fluid connector. Being similar functionally, in U.S. Pat. No. 4,030,494 to Tenczar disclosed is a fluid connector that is sealed by a resilient barrier of a flexible diaphragm type structure until assembled with another mating connector where in the resilient barrier is penetratable during assembly by the use of heat to fuse and sterilize the penetrated barrier, thus accomplishing what McKeon does, however, again with Tenczar being a one-time use and thus disposable.
A further specialized type of fluid connector is in U.S. Pat. No. 5,685,866 to Lopes that discloses a medical use valve that reseals after use i.e. for the adding of fluid medicine to a patients intravenous line without the risk of plug coring (from the syringe) contaminants entering into the patient through the intravenous fluid line. The point in Lopez is the ability to enter into a pressurized fluid line by inserting a syringe into a resilient medium that will seal around the syringe, while the syringe is passed through the resilient medium and into the open interior of the fluid line without the syringe cutting or dislodging any of the resilient medium into the fluid by use of a blunt nose syringe with a side discharge port. Another type of fluid tube connector for adjoining to a fixed port is in U.S. Pat. No. 5,536,049 to Coules et al. that discloses a flexible tube connector that is an outside diameter compression ferrule type that has a positive stop that limits engagement of the retaining member and the tube. The purpose in Coules et al., is in a positive stop that prevents damage to the tube by acting as a gage in limiting compression of the flexible tube, however, still resulting in a fairly complex assembly. Somewhat similar to Coules et al., in U.S. Pat. No. 5,868,440 to Kurz disclosed is a hose connector specifically for soft wall hoses for the purpose of minimizing cutting, leaking, and slipping of the hose to connector interface. Kurz utilizes a toroidal spring that is compressed in a frustroconical chamber against the hose to provide a sufficient wide area loading that is adequate for fluid sealing between the hose and the connector. Like Kurz, in U.S. Pat. No. 5,797,633 to Katzer et al. disclosed is a hose connector that uses pivotal gripping elements as against a frustroconical surface to compress the hose into the connector. Katzer et al. has the gripping elements in conjunction with the two part sleeve to control hose compression to prevent hose damage, however, again resulting in a multitude of complex parts.
In looking at simplified fluid connectors, in U.S. Pat. No. 4,215,119 to Mylett disclosed is a universal hose connector that has a frustroconical portion that has a series of circular barb rings to accommodate numerous sizes of hose diameters. Mylett has “sets” of increasing size circular barb rings that increases the bite of the barb ring into the tubing for retention purposes, however, a drawback of Mylett being that multiple engaging and disengaging would be difficult as the tubing would not easily disengage from the multiple barbs sets which would also have a tendency to damage the tubing due to their “shark teeth” type of profile.
What is needed is a simplified fluid connector without moving or separable parts that can accomplish a multiple use removable engagement of a fluid connection without replacing parts, can also have a substantially fluid tight sealed connection while at the same time minimizing the parts required for simplicity and reliability. In addition the fluid connector should have a firm engagement when manually assembled, while also being easy to manually disengage, without the need for tools in any case.